Vision changes linked to cognitive decline in Parkinson’s patients

Scientists may be able to predict who is at risk of dementia by studying the vision of patients with Parkinson’s

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Studying the vision of patients with Parkinson’s could enable scientists to identify those with a higher risk of dementia 18-months ahead of cognitive decline.

The findings by University College London researchers are outlined in papers published in Communications Biology and Movement Disorders.

Lead author Dr Angeliki Zarkali explained that people with Parkinson’s who have visual problems are more likely to get dementia and this appears to be linked to underlying changes in their brain wiring.

“Vision tests might provide us with a window of opportunity to predict Parkinson’s dementia before it begins, which may help us find ways to stop the cognitive decline before it’s too late,” Dr Zarkali said.

The Movement Disorders research revealed that in a group of 77 people with Parkinson’s disease, simple vision tests could predict who would go on to develop dementia within 18 months.

The Communications Biology study involved 88 people with Parkinson’s disease. Within this group, 33 people had visual dysfunction and were thought to be at higher risk of developing dementia.

MRI scans of the brains of these patients were compared to the scans of 30 healthy adults.

Scientists found that there was a higher degree of decoupling across the brains of those with Parkinson’s than healthy adults.

Those with visual dysfunction and Parkinson’s had more decoupling in some areas of the brain, particularly in regions associated with memory in the temporal lobe.

Dr Zarkali highlighted: “The two papers together help us to understand what’s going on in the brains of people with Parkinson’s who experience cognitive decline, as it appears to be driven by a breakdown in the wiring that connects different brain regions.”

A senior author on both the papers, Dr Rimona Weil, said that vision tests could be used to identify who should be targeted for new treatments to slow the progression of Parkinson’s.

“Ultimately, if effective treatments are found, then these simple tests may help us identify who will benefit from which treatments,” she said.